JP2020501338A - Composition for polymer-stabilized electrode reinforced with conductive flakes and method for producing the same - Google Patents

Abstract

Electrode films having high tensile strength and low electrical resistance are produced by using conductive flakes to strengthen polymer stabilized particle electrodes. Novel compositions and low energy methods are disclosed in the present invention. The method comprises mixing and stirring the particulate material and the fibrillable polymer with the conductive flakes into a paste, fibrillating the polymer, extruding and rolling the paste into a self-supporting electrode film; including. [Selection diagram] Fig. 1

Description

(Technical field)
The present invention relates to compositions for reinforcing polymer-stabilized particle electrodes, and to a method for the low-energy production of such compositions and electrodes, especially in energy storage devices.

(Background of the Invention)
There are a number of energy storage devices used to power modern technology, including capacitors (eg, electric double layer capacitors and lithium-ion capacitors), batteries (eg, lithium-ion batteries, and lithium-sulfur). Batteries), fuel cells, hydrogen storage devices, and the like. An electric double layer capacitor (EDLC), also called an ultracapacitor or a supercapacitor, is an energy storage device that can store more energy per unit volume and unit weight than conventional capacitors. Lithium ion batteries have very high energy densities, but have much lower power densities and shorter cycle life compared to EDLCs. The lithium ion capacitor has a hybrid structure of the EDLC and the lithium ion battery. Each type of device is associated with a positive electrode and a negative electrode that can be made from the same or different active materials. The compositions and methods of making such electrodes are important to the performance and cost of devices constructed for various applications.

  Currently commonly used electrode fabrication techniques include slurry coating and / or paste extrusion processes to produce electrode films. Both processes involve combining a binder, typically comprising a polymer or resin, particles of an active substance, and particles of a conductive material to form an electrode film. The binder provides a bond inside the obtained electrode film or between the current collector (typically an Al foil or a Cu foil) to which the electrode film is attached and the electrode film.

  In a slurry coating process, a liquid lubricant (typically organic, aqueous, or a mixture of aqueous and organic solvents) dissolves the binder in the resulting wet slurry containing the binder, active particles, and conductive particles. Used for The wet slurry is coated on the current collector by a doctor blade or slot die, after which the solvent is evaporated off and the film is dried. However, such a slurry-coated electrode film has a rigid porous structure and is easily affected by cracks or particle crushing from the current collector. Therefore, the electrode film is rarely used for a long period of time, deteriorating the energy, power, cycle life, and manufacturing harmony of the electrode. In addition, as the thickness of the electrode film decreases, it becomes more and more difficult to obtain a homogeneous layer, which requires high cost processes, huge capital investment and high quality control . Further, the slurry method for producing an electrode film cannot produce a rigid and self-supporting electrode film, which is desirable in terms of ease of application to a current collector and strength.

  Paste extrusion methods have been employed for the production of self-supporting electrode films in order to improve the electrode's resistance to cracking and particle crushing. In a self-supporting film, active particles (eg, activated carbon particles in EDLC) are bundled into a monolith by a fibrillable polymer binder (typically, polytetrafluoroethylene (PTFE)). Prior art paste extrusion processes for forming extruded electrode films involve either dry or, more typically, wet conditions in the presence of a liquid lubricant and under shear conditions. The binder and the active particles are stirred together. Liquid lubricants include hydrocarbons, defoamers, surfactants, high boiling solvents, dispersing aids, water, toluene, xylene, alcohols, glycols, ketones, naphtha, acetates, pyrrolidone, and isopar (Registered trademark). The resulting material has dough-like properties so that the material can be introduced into an extruder where the binder is fibrillated to form an extruded sheet. The extruded sheet can be calendered or roll pressed many times under heating and pressure before being pressed onto a current collector to be an electrode to produce an electrode film.

  In paste extrusion processes, fibrillable polymers, especially fluoropolymers such as PTFE, have been used extensively as particle stabilizers. Applying shear to the mixture of fibrillable polymer and active particles contributes to fibrillating the fibrillable polymer and forming an interconnected web-like self-supporting film that holds the particles together. Polymer stabilized electrode films are very flexible.

  When the film is attached to a current collector, the resulting electrode has high resistance to cracking and particle crushing. However, the self-supporting electrode film itself, while pliable during manufacture, is inherently soft and easily breaks or breaks prior to attachment to the current collector. Therefore, it is desirable to improve the tensile strength of the electrode film in the paste extrusion electrode manufacturing process to facilitate manufacturing, processing, handling, and assembling into other products.

  In the prior art, sintering is used to strengthen the bond between PTFE and active particles. The sintered paste is then stretched into an electrode film (US Pat. No. 4,194,040, US Pat. No. 3,864,124, and US Pat. No. 4,862,328). In another prior art, a second polymer is added to a PTFE active particle system to form a ternary system (US Pat. No. 6,127,474). The second polymer forms stronger fibers and reinforces the original system without the need for sintering of the primary particles themselves. In both cases, sufficient heating is required to soften and extrude the composition through the stirring, extrusion, and roll compaction processes. In addition, these second polymers are non-conductive materials. When a large amount of the second polymer is added, typically when it is added in an amount of 7% by weight or more, the conductivity of the electrode film is significantly sacrificed. Further, when the second polymer is pressed under heating, the second polymer tends to form a stretched film / cloth that blocks the surface of the active particles, thereby partially deactivating the active particles and causing the electrode to become inactive. Overall or device performance is sacrificed.

  In the prior art, the dry binder and dry active particles are agitated to form a paste at elevated temperatures without the addition of processing lubricants (US Pat. No. 7,295,423). However, this process requires precise control of temperature, relatively high temperatures, and relatively high pressures during extrusion and hot roll compaction, leading to a rather complex and energy intensive process.

  Heating typically softens the polymer, thereby facilitating the fibrillation process (in the extrusion and roll compaction steps). Therefore, the temperature needs to be higher than the polymer softening point. Depending on the type of polymer used, the temperature usually varies between 100 ° C. and 300 ° C. (US Pat. No. 6,127,474 and US Pat. No. 7,295,423). In the method of sintering (US Pat. No. 4,194,040, US Pat. No. 3,864,124, and US Pat. No. 4,862,328), the temperature used is sufficient to melt the polymer. High, typically above 300 ° C.

  In the industry, it is difficult to precisely control the temperature in a fibrillation process or an extrusion and roll compaction process. This is because the extruder or roll is made of metal or alloy and dissipates heat very easily. To address this, heated rolls, which are much more expensive than unheated rolls, have been used.

  Maintaining the high temperatures required during roll compaction and extrusion at atmospheric conditions leads to high energy consumption.

  Accordingly, there is still a need in the art for an improved composition and method using a paste extruded electrode manufacturing process that enhances a polymer-stabilized active particle electrode film that exhibits good electrical conductivity. And a need for a method.

  The present invention relates to a novel composition using conductive flakes and a low energy consumption method for forming a stabilized particle electrode film using a paste extrusion electrode manufacturing process.

  The present invention provides (a) mixing and stirring conductive flakes, active particles, at least one type of fibrillable polymer, and spherical conductive carbon particles to prepare a paste; (b) the paste (C) subjecting the extruded product to calendering or a roll to produce a self-supporting electrode film. In a preferred embodiment, the process comprises adding conductive flakes, active particles, at least one fibrillable polymer, and spherical conductive carbon particles to a liquid to prepare a paste prior to step (b). The method further comprises mixing and stirring in the lubricant.

  The tensile strength of the electrode film increases by at least 30% to 16 times (1600%) depending on the flake size and flake concentration. The enhanced film structure may allow the electrode film to be easily manufactured, processed, handled, and assembled into other products without the need for or with minimal heating. The three-dimensional conductive matrix provided by the conductive flakes reduces electrical resistance by more than 70%.

  It is to be understood that other aspects of the present invention will be readily apparent to those skilled in the art from the following detailed description, in which various embodiments of the invention are shown and described by way of example. is there. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various other respects, all without departing from the spirit and scope of the invention. It is. Accordingly, the drawings and detailed description should be regarded as illustrative in nature and not restrictive.

  For a more detailed description of the invention, briefly mentioned above, reference is made to the following drawings of specific embodiments of the invention. The drawings show only exemplary embodiments of the invention and therefore should not be considered as limiting its scope. The drawings are not necessarily to scale, and in some instances, proportions may be exaggerated to more clearly depict certain features.

FIG. 1 is a flow process diagram of the method of the present invention for making a polymer stabilized electrode film. FIG. 2 is an enlarged schematic plan view of a representative example of a preferred electrode film structure of the present invention. FIG. 3 is an enlarged schematic plan view of a representative example of the structure of another preferred electrode film of the present invention.

(Detailed description of the invention)
The following description and the embodiments described herein are provided as a means of describing one or more specific embodiments of the principles of the various aspects of the present invention. These examples are provided in various aspects, without limitation, for the purpose of illustrating the principles and the invention.

(Definition)
Electrode film, as used herein, refers to a self-supporting film extruded and pressed from a paste containing at least active particles and one or more binders without being attached to a current collector. As used herein, the term current collector refers to a highly conductive foil, such as a foil of Al, Cu, Ti, etc., used to conduct electrons from an electrode film. The term electrode as used herein refers to a sheet of electrode film mounted on a current collector. The term active particles as used herein refers to the active material in the form of powder or particles forming an electrode. For example, in EDLC, the active particles can be activated carbon particles. As another example, in a lithium-sulfur battery, the active particles may be sulfur-impregnated activated carbon particles.

  As used herein, the term fibrillable polymer refers to any polymer that can be sheared into long fibers. Spherical conductive particles are particles that add conductivity only to the electrode, and are typically considered to be spherical particles.

(Method of producing polymer-stabilized electrode film reinforced with conductive flakes)
The present invention relates to a novel composition using conductive flakes and a method of low energy consumption, which enhances polymer stabilized particle electrode films while forming a three-dimensional conductive matrix during the paste extrusion electrode manufacturing process.

  It can be seen that the compositions and methods of the present invention improve the tensile strength of the electrode film between 30% and 1600% with no or minimal heating required. It is believed that the three-dimensional conductive matrix provided by the conductive flakes reduces the electrical resistance of the resulting electrode by more than 70%.

  One embodiment of the method of the present invention comprises: (a) mixing and stirring conductive flakes, active particles, at least one fibrillable polymer, and spherical conductive particles to form a paste; (B) extruding the paste into an extruded product; and (c) producing the self-supporting electrode film by subjecting the extruded product to calendering or rolling. In a preferred embodiment, the process further comprises, prior to step (b), mixing and stirring the liquid lubricant with the other components of (a) to prepare a paste.

  One embodiment of the paste extrusion electrode manufacturing process of the present invention is illustrated in FIG. In step 1, active particles 101, at least one fibrillable polymer 102, and conductive particles 103 are mixed with conductive flakes 104 to prepare composition 100. In a preferred embodiment, a liquid lubricant 105 is added to the composition 100 to facilitate the mixing and agitating process to prepare the mixture 111. The mixture 111 is mixed and agitated 110 to prepare a preliminary fibril paste 112.

  The active particles 101 are an active material in a powder or particle state. The concentration of active particles in the composition 100 ranges from 60% to 99% by weight (% by weight), preferably from 80% to 90% by weight. The active particles may have a particle size between 1 and 50 microns, preferably in the range of 5 to 20 microns. Suitable active particles 101 include, but are not limited to, activated carbon particles, sulfur impregnated activated carbon particles, lithium-oxygen containing compounds, stabilized lithium metal powder, metal oxide particles, metal sulfide particles, metal nitride particles, And combinations thereof.

  At least one fibrillable polymer 102 is included in the composition 100 in an amount of about 0.1% to 15% by weight, preferably in an amount of 3% to 10% by weight. The fibrillable polymer is used as a particle stabilizer and forms a cobweb matrix of active particles 101 and conductive particles 103 after extrusion 120 and roll compaction 130 to form an electrode film. Examples of the fibrillable polymer 102 include, but are not limited to, polytetrafluoroethylene, polypropylene, polyethylene, copolymer, various polymer blends, natural or synthetic rubber, polyamide, polyurethane, liquid resin, silicone, elastomeric polymer, olefin polymer, and the like. Combinations.

  Spherical conductive particles 103 may have a particle size of less than 1 micron, and typically have a particle size in the range of 0.01 micron to 0.1 micron. The submicron conductive particles 103 are preferably spherical carbon particles, and may include, but are not limited to, carbon black particles, super P carbon particles, super C65 carbon particles, and combinations thereof. The concentration of the submicron spherical conductive particles in the composition 100 may range from 0.1% to 15% by weight, preferably from 1% to 10% by weight.

Referring now to the conductive flakes 104 in FIG. 1, the conductive flakes used in the composition of the present invention include metal flakes, preferably aluminum flakes, graphite flakes, graphene, expanded graphite flakes, conductive polymers Flakes, and combinations thereof. By adding 0.01% to 10% by weight, preferably 0.1% to 5% by weight, of conductive flakes to the composition 100, surprisingly, the tensile strength of the electrode film 131 is increased. Was significantly increased by the present inventors. As shown in Examples 1-9, similar compositions when made without conductive flakes typically have a tensile strength of about 0.03 kg / mm ² while the conductive the film having a flake has a greater tensile strength than 0.04 kg / mm ^2, more often been shown to have a tensile strength of from 0.05 kg / mm ² to 0.5 kg / mm ² I have.

  The increase in tensile strength is affected by the flake size. The conductive flakes used for the purposes of the present invention have a diameter in the range of 1 to 40 microns, and preferably have a diameter in the range of 5 to 20 microns. The thickness of the conductive flakes ranges from 0.001 micron to 5 microns, with the most preferred thickness being less than 1 micron. It can be seen that increasing the diameter of the conductive flakes from 6 microns to 15 microns increases the tensile strength of a 100 micron thick electrode film by 80%, as shown in Examples 1 and 4 herein below. The shape of the flakes is more preferably flat and microscopically enhances and enhances the shearing of the fibrillable polymer during the extrusion 120 and roll compaction 130 processes. This results in a stronger polymer matrix than without the addition of conductive flakes. In addition, a tight bond between the conductive flakes and the polymer fibers is observed, which likewise increases the strength of the overall matrix.

  On the other hand, when the diameter of the conductive flake is further increased, it is found that the tensile strength of the obtained electrode film is reduced due to the reduction amount of the conductive flake contained in the electrode film (Example 5). Increases in tensile strength are also affected by flake concentration. As shown in Examples 1 and 2, increasing the weight percentage of conductive flakes from 2% to 5% by weight increases the tensile strength of the electrode film.

  The submicron spherical conductive particles 103 will adhere to the fibrillated polymer fibers during extrusion 120 and roll compaction 130, providing conductivity along the fibrillation and roll compaction directions. However, because these conductive particles 103 are preferably spherical and small (submicron), the conductivity of the electrode film can be limited over the thickness of the film. The strong adhesion between the micron-sized conductive flakes and the fibrillated polymer fibers creates an advantageously large conductive path along the length of the film, especially along the thickness of the electrode film, whereby A three-dimensional conductive matrix connecting the conductive particles is formed through the conductive flakes and across the thickness of the film. Thereby, the electric resistance of the electrode film 131 similarly obtained decreases, and as a result, the electric resistance of the entire electrode decreases. In Examples 10-11, the electrical resistance of an 80 Farad electric double layer capacitor made from a 150 micron thick electrode film decreased by more than 70% when 5% by weight of conductive flakes were added to the composition. I do.

  It has also been shown that the addition of conductive flakes surprisingly improves the strength of the self-supporting film. Some slurry methods for making lithium-ion batteries use graphite flakes to improve conductivity, but there was no need or demand for film strength in the slurry method.

  The method of forming the composition 100 into a conductive self-supporting electrode film 131 can be performed in the presence of water or other liquid lubricant 105 and under shear conditions, either dry or more typically wet. One includes mixing and stirring 110 the components of the composition 100. The method then applies the agitated and prefibrillated paste 112 to the electrode film 131 by an extrusion process 120 and a calendering or roll compaction process 130 with no or minimal heating required. Including. As shown in FIG. 1, in step 2, the preliminary fibril paste 112 is extruded 120 into an extrudate 121, preferably in the form of an extruded sheet. In Step 3, the extruded product 121 is calendered or roll-compressed 130 a plurality of times to form a self-supporting electrode film 131.

  In a preferred embodiment, a liquid lubricant 105 is added to the composition 100 to aid pre-fibrillation during the agitation process 110 and to aid in fibrillation in the processing of extrusion 120 and roll compaction 130. . Preferred liquid lubricants 105 of the present invention include, but are not limited to, water, high boiling solvents, defoamers, dispersing aids, pyrrolidone mineral spirits, ketones, surfactants, naphtha, acetates, alcohols, Glycols, toluene, acetone, chloroform, xylene, Isopar®, and combinations thereof.

  In one preferred embodiment, the composition 100 of the present invention comprises from 80% to 85% by weight of 6 micron activated carbon activated particles 210 as active particles and from 5% to 10% by weight of polytetrafluorocarbon as a fibrillable polymer. It includes ethylene (PTFE) 220, 5% to 10% by weight of super P carbon particles 230 as spherical conductive particles, and 2% to 5% by weight graphite flakes 240 as conductive flakes. Ethanol can be used as a preferred liquid lubricant. When incorporating the mixture 111 into the electrode film, there is no need to heat during the processing of the agitation 110, extrusion 120, or roll compaction 130, thereby achieving a simplified, low energy consumption paste extruded electrode manufacturing process.

In industry, it is desirable for the electrode film to have a tensile strength greater than 0.01 kg / mm ² , preferably greater than 0.03 kg / mm ² , in order to easily process or process the paste into electrodes. . As shown in FIG. 2, by adding the conductive flake 240 to the structure 201, the tensile strength of the electrode film of the present invention from the present composition shows a value of 0.04 kg / mm ² or more, In most experimental tests, it exceeds 0.09 kg / mm ² (see Examples 1 to 7).

  In another preferred embodiment, the composition comprises from 80% to 85% by weight of 6 micron activated carbon as active particles 310, and from 3% to 5% by weight of polytetrafluoroethylene (PTFE) 320 and 2 as fibrillable polymer. 5% to 10% by weight of super P carbon particles 330 as spherical conductive particles, and 2% to 5% by weight of graphite flakes 340 as conductive flakes. Toluene or acetone is used as the liquid lubricant 105. When this mixture 111 is incorporated into the electrode film, no heating is required in the agitation 110, extrusion 120, or roll compaction 130 processes.

  Thus, the method of the present invention also exhibits relatively lower energy consumption than required for sintering or for heating with the addition of other binders. In most aspects of the invention, no heating is required, and if heating is used, it is limited to a stirring step and can be performed in a closed environment, such as a sealed chamber where heating can be limited and controlled. This is in contrast to pre-heating in extrusion and roll compaction processes that require excessive heat and provide limited heating control.

However, in an alternative embodiment, as shown in FIG. 3 and described in Examples 8-9, applying a minimal amount of heat during the extrusion 120 and roll compaction 130 processes will result in the final structure of the electrode film. the tensile strength at 301, it is possible to improve, for example, from 0.36 kg / mm ² to 50 kg / mm ^2.

  The present invention provides novel compositions and low energy consumption methods that use conductive flakes to strengthen polymer-stabilized particle electrodes while forming a three-dimensional conductive matrix during the paste extrusion electrode manufacturing process. The present invention limits the amount of heat and the second polymer used to achieve the required tensile strength, while maintaining the performance of the entire electrode or device.

  As shown again in FIG. 1, the stirring process 110 is typically performed with a stirrer capable of applying a shear force to the mixture 111. Examples of agitators include, but are not limited to, ball mills, jet mills, pin mills, impact mills, hammer mills, mechanical agitators, crushers, and grinders.

  The present invention may further include pressing the self-supporting electrode film 131 on the current collector to form electrodes for various uses. The current collector includes, but is not limited to, a metal foil or an alloy foil such as an aluminum foil, a copper foil, or a titanium foil; a metal mesh or an alloy mesh such as an aluminum mesh, a copper mesh, or a titanium mesh; Metal foil, and coated metal foil. An etched current collector, such as an etched aluminum foil, may be used to increase the adhesion of the electrode film 131 to the current collector. A thin layer of adhesive film may be coated on the current collector to increase adhesion and reduce interface resistance between the electrode film 131 and the current collector. The adhesive film may be a commercially available product (Acheson Colloids, Inc., 1600 Washington Ave., Port Huron, Michigan 48060, Phone: 1-800-984-5581 under the trade name "Electrodag® EEB-012"). "). The adhesive film can also be a carbon coating having a thickness of less than 10 microns.

  In addition to the application to the electrode film 131 in energy storage devices, these self-supporting films 131, which are affected by the type of active particles contained, can have faster absorption, such as gas filters, catalyst supports, liquid separation, and water treatment. , Desorption, or reaction rates, or in applications where better use and miniaturization of materials are desired.

  The present invention is described in more detail by the following examples.

(Example 1)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 8% by weight of super P carbon particles; 4) 2% by weight of graphite flakes (diameter) 6 microns).
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.05 kg / mm ² .

(Example 2)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight 6 micron activated carbon; 2) 10% by weight polytetrafluoroethylene (PTFE); 3) 5% by weight super P carbon particles; 4) 5% by weight graphite flakes (diameter) 6 microns).
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.09 kg / mm ² .

(Comparative Example 3)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 10% by weight of super P carbon particles. No conductive flakes.
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.03 kg / mm ² .

(Example 4)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 8% by weight of super P carbon particles; 4) 2% by weight of graphite flakes (diameter) 15 microns).
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.09 kg / mm ² .

(Example 5)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 8% by weight of super P carbon particles; 4) 2% by weight of graphite flakes (diameter) 50 microns).
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.04 kg / mm ² .

(Example 6)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 6% by weight of super P carbon particles; 4) 4% by weight of graphene.
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.10 kg / mm ² .

(Example 7)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 8% by weight of polytetrafluoroethylene (PTFE); 3) 7% by weight of super P carbon particles; 4) 5% by weight of aluminum flakes (diameter) 15 microns).
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.12 kg / mm ² .

(Example 8)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 5% by weight of polytetrafluoroethylene (PTFE); 3) 3% by weight of polyethylene; 4) 8% by weight of super P carbon particles; 5) Contains 4% by weight of graphite flakes.
Five times the total weight of components 1) -5) toluene was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The obtained tensile strength of the electrode film is 0.36 kg / mm ² .

(Example 9)
Activated carbon electrode film:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 5% by weight of polytetrafluoroethylene (PTFE); 3) 3% by weight of polypropylene; 4) 7% by weight of super P carbon particles; 5) Contains 5% by weight of graphene.
Acetone / ethanol 5 times the total weight of components 1) -5) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring with minimal heating, the mixture becomes a paste, which is then extruded and roll compacted into a 100 micron thick self-supporting film.
The obtained tensile strength of the electrode film is 0.50 kg / mm ² .

(Example 10)
Activated carbon electrode:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 5% by weight of super P carbon particles; 4) 5% by weight of graphene.
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 150 micron thick self-supporting film (no heating).
The electrode film having a thickness of 150 μm is pressed into an adhesive film-coated Al foil (15 μm) serving as an electrode.
An 80 Farad electric double layer capacitor (EDLC) was made from the electrodes.
The resulting electrical resistance of the 80 Farad EDLC was 7.5 mΩ.

(Comparative Example 11)
Activated carbon electrode:
The composition comprises: 1) 80% by weight of 6 micron activated carbon; 2) 10% by weight of polytetrafluoroethylene (PTFE); 3) 10% by weight of super P carbon particles. No conductive flakes.
Ethanol at 5 times the total weight of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 150 micron thick self-supporting film (no heating).
The electrode film having a thickness of 150 μm is pressed into an adhesive film-coated Al foil (15 μm) serving as an electrode.
An 80 Farad electric double layer capacitor (EDLC) was made from the electrodes.
The resulting electrical resistance of the 80 Farad EDLC was 25 mΩ.

(Example 12)
Sulfur impregnated activated carbon electrode film:
The composition comprises: 1) 80% by weight sulfur-impregnated activated carbon; 2) 10% by weight polytetrafluoroethylene (PTFE); 3) 7% by weight super P carbon particles; 5) 3% by weight graphite flakes.
Five times the total weight of water of components 1) -4) was added to the composition as a liquid lubricant to prepare the mixture.
After stirring, the mixture becomes a paste, which is then extruded and roll compacted at room temperature into a 100 micron thick self-supporting film (no heating).
The resulting tensile strength of the self-supporting film is 0.10 kg / mm ² .
The electrode film having a thickness of 100 μm is pressed into an adhesive film-coated Al foil (15 μm) serving as a cathode of a lithium-sulfur battery.
The resulting cathode exhibits a high capacity of 1,236 mAh / g (sulfur) and has a high load of more than 5 mg (sulfur) / cm ² .

Claims (55)

A method for producing an electrode film suitable for use as an electrode,
A step of preparing a pre-fibrillated paste by stirring a composition comprising the following steps (a) and below:
(I) more than 60% by weight of active particles;
(Ii) up to 15% by weight of at least one fibrillable polymer binder;
(Iii) 15% by weight or less of spherical conductive particles, and
(Iv) 10% by weight or less of conductive flakes,
(B) extruding the paste into an extruded product, and
(C) a step of rolling the extruded product to produce an electrode film.
Wherein the extrusion and roll compaction contribute to fibrillation of the fibrillable polymer binder.   The activated particles are activated carbon particles, sulfur-impregnated activated carbon particles, lithium-oxygen-containing compound, stabilized lithium metal powder, metal oxide particles, metal sulfide particles, metal nitride particles, and a combination thereof. The method of claim 1, wherein the method is selected.   The method of claim 1, wherein the particle size of the active particles ranges from 1 to 50 microns.   4. The method of claim 3, wherein the active particles have a particle size in the range of 5-20 microns.   The fibrillable polymer is a group consisting of polytetrafluoroethylene, polypropylene, polyethylene, copolymer, various polymer blends, natural or synthetic rubber, polyamide, polyurethane, liquid resin, silicone, elastomer polymer, olefin polymer, and combinations thereof. The method of claim 1, wherein the method is selected from:   The method according to claim 1, wherein the conductive particles are spherical conductive particles.   The method of claim 6, wherein the spherical conductive particles are selected from the group consisting of carbon black particles, super P carbon particles, super C65 carbon particles, and combinations thereof.   The method of claim 7, wherein the spherical conductive particles have a particle size of less than 1 micron.   9. The method of claim 8, wherein the spherical conductive particles have a particle size ranging from less than 0.01 microns to 0.1 microns.   The method according to claim 1, wherein the conductive flakes are selected from the group consisting of metal flakes, preferably aluminum flakes, graphite flakes, graphene, expanded graphite flakes, conductive polymer flakes, and combinations thereof.   The method of claim 10, wherein the conductive flake has a diameter in the range of 1 to 40 microns.   The method of claim 11, wherein the conductive flake has a diameter in the range of 5-20 microns.   The method of claim 10, wherein the thickness of the conductive flake ranges from 0.001 micron to 5 microns.   14. The method of claim 13, wherein the thickness of the conductive flake is less than 1 micron.   The method of claim 1, further comprising adding a liquid lubricant to the composition.   16. The method of claim 15, wherein the liquid lubricant is added in a proportion of up to 5 times the weight of the other components in the composition.   The liquid lubricant is water, a high boiling point solvent, an antifoaming agent, a dispersing aid, a pyrrolidone mineral spirit, ketones, a surfactant, naphtha, acetates, alcohols, glycols, toluene, acetone, chloroform, xylene, 17. The method of claim 16, wherein the method is selected from the group consisting of Isopar (R) and combinations thereof.   The method of claim 1, wherein the step of stirring is performed in a stirrer capable of applying a shear force to the composition.   19. The method according to claim 18, wherein the stirrer is selected from the group consisting of a ball mill, jet mill, pin mill, impact mill, hammer mill, mechanical stirrer, crusher, and grinder.   The method of claim 1, wherein extruding and roll compacting the fibrillated composition is performed at room temperature.   The method of claim 1, wherein the steps of extruding and roll compacting the fibrillated composition are performed at a temperature and pressure corresponding to the softening point of the fibrillable polymer. The method of claim 1, wherein the electrode film has a tensile strength greater than 0.04 kg / mm ² . The electrode film has a higher tensile strength than 0.09 kg / mm ^2, The method of claim 22.   The method of claim 1, further comprising pressing the electrode film onto a current collector to form an electrode for use in an energy storage device.   The method of claim 24, wherein the current collector is selected from the group consisting of a metal foil, an alloy foil, a metal mesh, an alloy mesh, a conductive carbon cloth, an etched metal foil, and a coated metal foil.   26. The method of claim 25, wherein the metal foil and the alloy foil are selected from the group consisting of aluminum foil, copper foil, and titanium foil.   26. The method of claim 25, wherein the metal mesh and the alloy mesh are selected from the group consisting of an aluminum mesh, a copper mesh, and a titanium mesh.   26. The method of claim 25, wherein the etched metal foil is selected from the group consisting of an etched aluminum foil, an etched copper foil, and an etched titanium foil.   26. The method of claim 25, wherein the coated metal foil is selected from the group consisting of a carbon coated metal foil and an adhesive film coated metal foil.   The method according to claim 1, wherein the device is selected from the group consisting of an energy storage device, a filter, and a catalyst support.   The method of claim 24, wherein the energy storage device is selected from the group consisting of an electric double layer capacitor, a lithium-sulfur battery, a lithium-ion battery, a lithium-ion capacitor, a fuel cell, and a hydrogen storage device. An electrode film suitable for use as an electrode,
(A) more than 60% by weight of active particles,
(B) up to 15% by weight of at least one fibrillable polymer binder;
(C) 15% by weight or less of spherical conductive particles, and
(D) 10% by weight or less of conductive flakes;
And an electrode film.   The active particles are a group consisting of activated carbon particles, sulfur-impregnated activated carbon particles, lithium-oxygen containing compound, stabilized lithium metal powder, metal oxide particles, metal sulfide particles, metal nitride particles, and combinations thereof. 33. The electrode film of claim 32, selected from:   33. The electrode film according to claim 32, wherein said active particles have a particle size in the range of 1 to 50 microns.   35. The electrode film of claim 34, wherein said active particles have a particle size in the range of 5-20 microns.   The fibrillable polymer is a group consisting of polytetrafluoroethylene, polypropylene, polyethylene, copolymer, various polymer blends, natural or synthetic rubber, polyamide, polyurethane, liquid resin, silicone, elastomer polymer, olefin polymer, and combinations thereof. 33. The electrode film according to claim 32, selected from:   33. The electrode film according to claim 32, wherein the conductive particles are spherical conductive particles.   38. The electrode film of claim 37, wherein the spherical conductive particles are selected from the group consisting of carbon black particles, super P carbon particles, super C65 carbon particles, and combinations thereof.   39. The electrode film of claim 38, wherein said spherical conductive particles have a particle size of less than 1 micron.   40. The electrode film of claim 39, wherein said spherical conductive particles have a particle size ranging from less than 0.01 microns to 0.1 microns.   33. The electrode film of claim 32, wherein the conductive flakes are selected from the group consisting of metal flakes, preferably aluminum flakes, graphite flakes, graphene, expanded graphite flakes, conductive polymer flakes, and combinations thereof. .   42. The electrode film of claim 41, wherein said conductive flakes have a diameter in the range of 1 to 40 microns.   43. The electrode film of claim 42, wherein said conductive flakes have a diameter in the range of 5-20 microns.   43. The electrode film of claim 42, wherein said conductive flakes have a thickness in the range of 0.001 micron to 5 microns.   The electrode film of claim 44, wherein the thickness of the conductive flake is less than 1 micron. The electrode film has a higher tensile strength than 0.04 kg / mm ^2, the electrode film of claim 32. The electrode film has a higher tensile strength than 0.09 kg / mm ^2, the electrode film of claim 46.   33. The electrode film of claim 32, wherein said electrode film is pressed onto a current collector to form an electrode used in an energy storage device.   49. The electrode film according to claim 48, wherein the current collector is selected from the group consisting of a metal foil, an alloy foil, a metal mesh, an alloy mesh, a conductive carbon cloth, an etched metal foil, and a coated metal foil. .   50. The electrode film according to claim 49, wherein the metal foil and the alloy foil are selected from the group consisting of an aluminum foil, a copper foil, and a titanium foil.   50. The electrode film according to claim 49, wherein the metal mesh and the alloy mesh are selected from the group consisting of an aluminum mesh, a copper mesh, and a titanium mesh.   50. The electrode film of claim 49, wherein the etched metal foil is selected from the group consisting of an etched aluminum foil, an etched copper foil, and an etched titanium foil.   50. The electrode film according to claim 49, wherein the coated metal foil is selected from the group consisting of a carbon coated metal foil and an adhesive film coated metal foil.   33. The electrode film of claim 32, wherein said device is selected from the group consisting of an energy storage device, a filter, and a catalyst carrier.   49. The electrode film according to claim 48, wherein the energy storage device is selected from the group consisting of an electric double layer capacitor, a lithium-sulfur battery, a lithium-ion battery, a lithium-ion capacitor, a fuel cell, and a hydrogen storage device. .